Bridge falsework tower



Oct. 29, 1929. o. J. MARSTEN 1,733,505

BRIDGE FALSEWORK TOWER Filed June 2, 1927 7 Sheets-Sheet 1 INVENTOR Oct. 29, 1929. o. J. MARSTEN 1,733,505

BRIDGE FALSEWORK TOWER Filed June 2, 1927 7 Sheets-Sheet a Oct. 29, 1929. O J MARSTEN 1,733,505

BRIDGE FALSEWORK TOWER Filed June 2, 1927 v She ets-Sheet 4 M'Tif JNVENTOR 016 J MWSQII/I.

Oct. 29, 1929. o. J. MARSTE N 1,733505 BRIDGE FALSEWORK TOWER Filed June 1927 '7 Sheets-Sheet 5 INVENTOR 0Z6 JManskn.

Oct. 29, 1929. o. J. MARSTEN 1,733,505

BRIDGE FALSEWORK TOWER Filed June 1927 7 Sheets-Sheet 6 ATTORNEY Oct. 29, 1929. o, J MARSTEN BRIDGE FALSEWORK 'rowsn Filed June 2, 1927 7 Sheets-Sheet 7 INVENTOR 016 J file/193610.

Patented Oct. 29, 1929 UNITED STATES PATENT OFFICE OLE J. MARSTEN, OF BETHLEHEM, PENNSYLVANIA, ASSIGNOB T BETHLEHEI STEEL COMPANY, A CORPORATION 01 DELAWARE BRIDGE IALSEWORK TOWER Application filed June 2, 1927. Serial No. 195,891.

My invention relates to falsework towers and particularly to temporary supports in the erection of permanent structures such as bridges, trusses, or other overhead structures.

The towers usually consist of a series of cribs, supporting vertical bents on which the overhead structure rests during its course of erection.

When erecting a bridge or other overhead 0 structures embodying comparatively long spans supported on piers, it is necessary to first temporarily trestle or falsework the openings between the piers and such falsework should be of sufficient strength to carry the weight of the permanent structure together with the weight of the erection equipment. Such trestles or falsework must be founded upon the floor of the river or chasm to be bridged. In cases where the floor or bottom is hard or rocky with insuflicient thickness of softer materials to give lateral support to piles it is necessary to employ special measures to insure safe supports, particularly where water of consi erable ourrent exists.

Heretofore, in the erection of a bridge across a river having a rocky bottom, it has been customary to construct heavy wooden cribs which are floated to the site of the bridge and sunk by means of stones or other ballast material, to provide a foundation for the falsework. After the bridge is complete, the falsework must be dismantled, the stone removed from the crib and the crib taken out.

The crib and its ballast form an obstruction in the river passage and it is often necessary to dredge the river in order to entirely remove the obstruction. With cribs of this character, it is usually necessary to place *0 heavy anchors upstream to guide and hold the crib While it is being floated into position. Furthermore, cribs of this type cannot be conveniently taken up and moved to another position, so it is necessary to place a crib at each point of erection.

One of the objects of my invention is to rovide a metal crib or framework which is adapted to be constructed at a point remote from the permanent structure to be erected,

5 and transported and placed in position at the site of said structure to afford a foundation for the falsework to be used during the erection of said structure.

Another object of my invention is to rovide a crib which will not slip on rocky ttom, and also offers minimum resistance to the current or dbris floating in the water.

A further object of my invention is to provide a pile frame structure that is adjustable in a vertical plane relative to the mean ground or water level.

A still further object of my invention is to provide a crib that can easily be taken up and moved along to another position as erection progresses, and which can be quickly and cheaply removed after erection is completed.

The novel features will be more fully understood from the followin description and claims taken with the drawings.

Fig. 1 illustrates diagrammatically a method of placing pile frames in arch spans when starting erection from a shore line ier;

Fig. 2 illustrates diagramatically an e evation of an arch span with the falsework towers assembled beneath the span;

Fig. 3 illustrates diagramatically a plan view of the cribs and bracin Fig. 4 is an elevation of a typical falsework tower and section through an arch span showing a portion of a traveler on top of the span;

Fig. 5 is an end view of a typical falsework tower assembled beneath a span;

Fig. 6 is a plan View of a pile frame, showing its piles in place;

Fig. 7 is an elevation of a pile frame with its l:piles in place;

ig. 8 is an end view of a pile frame with its piles and cross beams connecting upper ends of piles; 90

Fig. 9 is a detail of connection for maximum distance from top of cross beam to bottom of pile;

Fig. 10 is a detail of connection for minimum distance from top of cross beam to bot- 95 tom of pile;

Fig. 11 is a typical connection of top struts to cap on top of bent;

Fig. 12 is an end view of the upper portion of a pile frame and shows a cross beam con- 1 0 nected to its piles, and pile frame hangers for suspending the pile frame from the upperbetween a structure member and a san jack the sand jack resting on the top members 0 a bent; and,

Fig. 16 is a transverse sectional view on line XVIXVI of Fig. 15 of a bearin block supported by a sand ]8.Ck, and a hy raulic jack inside of the bearing block.

Referring now to the drawings: The numeral 1 designates the crib or pile frame which is thorou hly braced to resist vertical, lon itudinal and transverse forces, as shown in igs. 6, 7 and 8. The frame 1 is provided with vertical guideways 2 to receive and hold in position a number of piles 3. Along the top edges of the frame are attached brackets 4 to which are connected struts 5, which anchor the first pile frame 1 to a fixed point 6 of the bridge structure and also connect the pile frames to each other. At eachcorner of the frame 1, there is provided an opening 7 for the attachment of the diagonal guy lines 8. It will be seen that the pile frame constitutes an openwork structure which offers a minimum resistance to the current of the river or dbris floating in the water.

As shown in Figs. 6, 7 and 8, each pile 3 is referably of. H-section, pointed and reinorced by T-shaped pieces at its bottom end for a rock bottom or it may be adapted to a spread ooting if the bottom is of a soft foundation. Between the upper ends ofopposite piles as shown in Fig. 8, are secured transverse beams 9 which carr the load imposed upon the bents 10, whic in turn support the bridge structure 11. The connec tions between the piles and the cross beams 9 are adjustable by means of adjustable connecting angles 26 which are bolted to the webs of the iles 3 as shown in Figs. 9 and 10, so that t e tops of the beams 9 can be brought to a desired level notwithstanding the irregularities of the bottom.

The bents 10, as shown in Figs. 4 and 5 are preferably portable structures comprising a air of s aced vertical le s which are suitab y braced laterally and o a length to suit the elevation of the arches. At the top of each bent near its ends, (see Fig. 11) there is provided connection plates 28 to secure, by means of struts 15, the cap of a bent to a fixed point 6 on the bridge structure and to tie the caps of adjacent bents 10 to each other.

The crib 1 is hung from the vertically adjustable brackets 29 which are attached to each of the outside corner piles, as shown in Fig. 12. Trunnion blocks30 are mounted on the brackets 29 and support the ad'ustable bolts 31 having shackles 32. A cable 33 connects the shackles 32 to a member 34 of the pile frame 1. By this means the ile frames 1 are adjusted to a desired leve above the surface of the water 37 or ound line 35.

In order to assure that t e piles in frame 1 provide a solid support for the bent 10, blocking and wedges 13 are placed between the bent 10 and the transverse beams 9. Blocking 12 is placed between the latter and the top of pile frame 1, as clearly shown in Fig. 13, and the parts are secured together by means of steel rope and shackle tiedown 14. In .order to resist the movement of the pile frames in the direction of the river current while being lowered into the water, the end pile frame is anchored to the ier and the frames are tied to one another y means of diagonal ties 8, as shown in Fig. 14. The ties 8 are attached to brackets 16 by means of the shackles 17 and preferably consist of a twopartsteel cable connected together by means of a turnbuckle 18.

To obtain a point contact between the structure members 19 and the supporting falsework, and to allow for the angularity of the structure with respect to the bents, bearing blocks 20 are attached to the underside of the members 19, and the blocks rest on sand jacks 21 which are supported on the top of the bents 10. Each bearing block 20 is preferably a steel casting, flat on the top, with two vertical webs 22 reinforced with transverse ribs 23. The bottom ortion of the vertical webs 22 are of cylin rical shape to obtain a bearing in a line normal to the structure 19 and the bent 10. A cylindrical sha d portion 24 between the vertical webs 22 m provided to afford a bearing oint for a h draulic jack 25 when place between t e bearin block and the sandjack 21. To one end 0 the bearing block 20 is attached an adjustable link, pinned to a connection plate 36, which in, turn is secured to a member of the bridge structure. This device is to hold the bearing block from slipping due to the angularity of the bridge structure, and for the purpose of adjusting the block relative to the adjacent bent.

Referring to Fig. 1, in the erection of a bridge falsework tower, a ile frame 1 completely assembled, is. loade onto a dolly car (not shown) and run out on the structure near the point of erection, and then it is lifted from the dolly car by the traveler A. The frame is now swung clear of the end of the structure and held in suspension while a derrick car B, operating underneath the traveler, places the four corner piles 3 into the frame. The pilesare held in position by means of maasoa bolts inserted in the top holes of the piles. The frame 1 is now lowered to a osition immediately above the water line 3 and with the assistance of the derrick car I3, struts 5 are attached to the pile frame at brackets 4 the other ends of the struts being attache to a fixed point 6 of the bridge structure es-- tablish a fixed relation between the frame 1 and structure. As the frame 1 is lowered into the water, it is brought into a definite position relative to the bridge. A diagonal uy line 8, (see Fig. 14) one end attached to the pile frame and the other end secured to the fixed structure resists the movement of the crib in the direction of the current. The remaining iles are placed in the frame by means of t e. traveler A and tapped with a weight to ensure proper bearing. The transverse beams 9 are attached to the top of the ilw 3 and the necessary blocking 12 and 13 placed for the erection of the bent 10. In the same manner above referred to, the top end 28 of the bent is secured to a fixed point 6 of the bridge structure by means of strut connections 15, (see Figs. 2 and 11). Sand jacks 21 supported on blocking across the top members of the bent 10 complete the tower when in contact with the cylindrical bearin blocks 20- attached to the longitudinal mem ers 19 of the bridge structure. The succeeding towers are erected in a similar manner, and the upper ends of the bents are linked together by means of struts 15.

The dismantling of the falsework towers consists of substantially the reverse operation of erection as above described, with the exception that the bent 10 is disassembled and lifted up through the bridge structure piece by piece and the pile crib 1 is lifted from its position in the water, swun clear of the side of the bridge and hoiste to a resting place on top of the permanent structure.

It can be readily seen by those skilled in the art that my method of constructing and erecting falsework towers is a decided improvement over existing methods, inasmuch as the cribs and bents can be fabricated on shore, carried out into the structure under erection, lowered and secured into fixed position, taken up and moved to another positlon as required, without having to prepare any up-stream anchors or undergo any subsequent dredging. While special reference has been made to the use of falsework towers for erecting structures above a body of water, it is to be understood that their use is not to be limited to that extent, but that the towers may be employed in the erection of overhead structures on land as well.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire therefore, that only such limitations shall be placed thereupon as are imposed by the rior art or as are specifically set forth in t e appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A pile frame for falsework towers, comprising a framework having guideways and means mounted in said guideways for supporting a bent.

2. A falsework structure, comprising a plurality of spaced and interconnected portable frames, piles mounted in said frames, members supported on said piles and bents supported on said members.

3. A falsework structure, comprising a portable metallic frame having a plurality of guideways, piles slidably mounted in said guideways, and means at the upper ends of said piles for adjustably supporting a cross beiim between a pair of oppositely disposed p1 es.

4. Pile frames for a falsework structure, comprising a plurality of spaced metallic frames, means for connecting and spacing said frames at fixed intervals, a plurality of vertical metallic piles slidably mounted in said frames, and transverse members secured between said piles, thus forming a crib or series of cribs adapted to support bents of a falsework structure.

5. In a bridge falsework tower, the combination of a portable frame adapted to guide a plurality of piles, a fixed member, means for adjustably securing the frame to a pile, a strut, one end of said strut being attached to said fixed member and the other end attached to said frame, and a guy line tying one end of the frame to said fixed member a bent supported on said piles and a secon strut, one end of said second strut being attached'to said fixed member and the other end attached to said bent.

6. In combination, a series of cribs arranged in a row, a series of bents mounted on said cribs, struts connecting the cribs, other struts to connect said bents, and diagonal guy lines between adjacent cribs.

7. In combination, a crib, a bent supported on said crib, a bridge member, a bearing block attached to said member, and a sand jack supported on said bent for supporting said bridge member.

8. In combination, a frame having guideways, piles mounted in said guideways, means to support said frame on said piles, a member supported on said piles, a bent supported on said member, a bridge structure, a bearing block on said bridge structure and positioned over said bent, and means to anchor said frame and said bent to said bridge structure.

9. A falsework structure comprisin a frame having guideways, piles mounte in said ideways, means to adjustably attach said rame to said piles, a transverse member, means to adjustably attach said transverse member to said piles, and a bent mounted on said transverse member.

10. In combination with a bridge structure of a falsework structure comprising, a

series of individual interconnected frames having guideways, piles mounted in said guideways, means to attach said frames to said piles, transverse members secured to said iles, bents mounted on said transverse memers, means to interconnect said bents and means to anchor said frames and said to said bridge structure. 11. In combination, a frame, a pluralit of piles slidabl mounted in said frame, a ent SllIgJOltBd on said piles, a jack supportedon sai bent, a bridge member, and a bearing block attached to the latter member adapted to rest on said jack.

12. In asup orting structure, a frame comprising space longitudinal members rovided with guideways intermediate t eir ends, piles mounted in said guideways, and means to fasten said frame to said piles.

In testimony whereof I hereunto aflix my signature.

OLE J. MARSTEN.

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